It has become customary in automobiles and other vehicles to utilize a stop/brake light which is located high on the rear of the vehicle and is centered for improved visibility. The stop light may, for example, be located in the rear window. In sport-utility vehicles which have a tailgate, the stop light may be located above the rear window. Such stop lights are typically elongated and may be twenty-or more inches long. In order to achieve uniform illumination over this length, neon lamps may be used. In general, neon lamps have relatively low power consumption and long operating lives.
It has been proposed in the prior art to use neon lamps for signaling in vehicles. A neon lamp direction signal, including arrows for indicating direction, is disclosed in U.S. Pat. No. 1,792,599 issued Feb. 17, 1931 to Murray. The disclosed lamp also includes a stop signal indication. A neon sign, including a neon lamp tube for mounting in the window of an automobile, is disclosed in U.S. Pat. No. 1,854,654 issued Apr. 19, 1932 to Koch, Jr. et al. A neon lamp signaling device for mounting in the rear window of a vehicle is disclosed in U.S. Pat. No. 1,839,499 issued Jan. 5, 1932 to Rava. A rare gas automobile indicator light system employing a single, horizontally disposed indicator tube operated to provide braking, parking, emergency flasher and turn indications is disclosed in U.S. Pat. No. 4,682,146, issued Jul. 21, 1987 to Friedman, III.
A lamp assembly utilizing an elongated neon lamp tube must meet several requirements for successful application in vehicles. The neon lamp must be able to withstand a high level of shock and vibration without degradation in performance, particularly when it is mounted in a sport-utility vehicle that may be used in rough terrain. The lamp assembly must operate without interruption under high and low temperature conditions that result from the environment and from heat generated by the neon lamp. Furthermore, the lamp assembly must be protected against moisture and high humidity conditions. In addition, neon lamp assemblies for use in vehicles should be simple in construction and low in cost.
Neon lamps may be energized at a frequency on the order of 60 kHz. The starting voltage may be on the order of 3 kilovolts, and the operating voltage may be on the order of 1 kilovolt. It is important to ensure that the neon lamp assembly does not emit radiation which may potentially interfere with nearby electronic equipment in the vehicle, in other vehicles and in adjacent buildings. A pilot lamp fixture having a transparent conductive shield for reducing or eliminating RF interference is disclosed in U.S. Pat. No. 3,801,808, issued Apr. 2, 1974 to Johnson. A headlamp for motor vehicles, including a gas-discharge lamp, a glass or plastic screen and a metallic coating for shielding interference radiation, is disclosed in U.S. Pat. No. 5,287,258, issued Feb. 15, 1994 to Remus.